Measurement and regulation of flow of steam or other fluid



Jan. 1, 1929. 1,697,344

G. CAMPBELL MEASUREMENT AND REGULATION OF FLOW OF STEAM OR OTHER FLUID Filed July 6, 1926 2 Sheets-Sheet 1 INVENTOR A TTORNE VS.

I Jan.

G. CAMPBELL MEASUREMENT AND REGULATION OF FLOW OF STEAM OR OTHER FLUID Filed July 6, 1926 2 Sheets$heet 2 G INVEAIQZIQ.

BY ROS/UV) M 84 A TTORNE Y8.

Patented J an. 1, 1929.

UNITED STATES 1,697,344 PATENT canes.-

GRANT CAMPBELL, OF SHORT HILLS, NEW JERSEY, ASSIGNOR TO CAMPBELL ENGI- NEERING COMPANY, OF SHORT HILLS, NEW JERSEY, A CORPORATIONOF NEW JERSEY.

MEASUREMENT AND REGULiATION OF. FLOW 0F STEAM OR OTHER IL'lTID.

Application filed July 6,

unit of time is indicated or gaged and may be v adjusted to a desired rate; for example, in the case of steam, dealing with flow in pounds per hour, in accordance with the common practise in the industries. The invention has reference particularly to the measurement or regulation of flow of an elastic fluid or gas,

' although it will be understood that the prinrepresented herein by dry saturated steam,

ciples are applicable for the measurement 0 other fluids. By measurement is meant ,the mere indicating or metering of the rate of flow by any indicating device or gage, and by regulating is meant the intentional or useful varying or adjusting of the rate of flow by the aid or under the control of the flow meas uring or indicating device or gage.

The invention has a wide field of utility, and has been successfully employed for example where steam, having a high initial or boiler pressure, is desired to be delivered to a receiving vessel or system at a substantially lower pressure, wherein the steam is utilized for example in carrying out a process such as the refining of oils. The invention applies more particularly to cases where the flow of the fluid or steam is from a higher pressure to a lower pressure not more than 58% of the higher pressure. Another industrial application of the invention is to indicate the rate of consumption of steam by some process or apparatus, for example, a low pressure vessel located remote from a central point. Other uses will be mentioned hereinbelow and further ones will suggest themselves.

The general object of the invention is to afford a system or means of measurement or gagingof the rate of flow of steam or other elastic fluid which will be not merely efficient and substantially accurate, but simple, durable and convenient of use and operation.

Further and more particular objects and ad vantages will be explained in the hereinafter following description of several embodiments of the invention, or will be apparent to those skilled in the subject. To the attainment of the objects and advantages referred to the present invention consists in the novel sys- 1926. Serial No; 120,691.

tem of measurement and regulation of flow of steam or other fluids, and the novel features of method, apparatus, operation, arrangement, combination and detail herein illustrated or described.

This application is in part a continuation 60 of my prior application Serial Number 86,928, filed June 13, 1925 for orifice element and system and methods and aplparatuses utilizing the same; Figs. 2 and 3 ereof for example corresponding with Figs. 8 and 7 respectively of said prior application.

In the accompanying drawings Fig. 1 is a more or less diagrammatic view partly in 4 side elevation and partly in central section of f a simple form of apparatus illustrating the principles of the present inventon.

Fig. 2 is a similar view of a diflerent embodiment containing the features shown in Fig. 1 combined with other features, as will be niore fully explained.

Fig.3 is a smaller view showing a further modification or application of the invention.

Fig. 4c is a similar view showing a further modification or application of the invention.

Fig. -5 shows a gage dial or face that may be used with the Fig. 4 gage.

Fig. 6 shows a recording ga e which may be substituted for the mere 1n icating gage, for example of Fig. 4.

In one aspect this invention, in the disclosed embodiment, is based upon the law that when an elastic fluid such as dry steam or gas is discharged through an orifice from a higher to a lower pressure, the lower pressure being not more than 58% of them higher pressure, referring to absolute pres sures, the rate of 'flow through the orifice is a direct function of, or varies directly with, the degree of the-higher pressure and the efi'ective area of the orifice; for example in the case of steam the flow in pounds per second substantially equals the. higher absolute pressure in pounds per square inch, multiplied by the orifice area in square inches, divided by 70 and the pounds of steam flowing per hour will be 3600 times this figure.

According to the present invention, in its basic form, an orifice is used, taking the case of steam, having an effective area of .0195

square inch approximately, (e. g. circular diameter .1566 inch) this giving the result that by merely gaging thepressure preceding the orifice by'means ofa pressure gage gradu- Fig. 1, and it affords a mere measurement or gaging, without means of adjusting the flow. The high pressure of inlet pipe 10 delivers the steam or other fluid to the orifice element or unit 11, which is a chambered vessel with bulging walls affording substantial capacity. This pressure chamber is shown formed with a 'boss 12 at one side tapped to. receive a pipe or connection 13 to a pressure gage 14. The high steam pressure may vary, and the gage,

. by its index or pointer 15, will at all times indicate the existing pressure in the chamber.

The gage may have the usual graduations or dlvision marks 16 in connection with a series of indicating numbers 17 by which the pressure readings are taken. It is .to be understood that the gage difli'ers from-the ordinary pressure gage in that it is set to read I absolute pressure, or approximately 14.7 pounds per square inch greater than the usual gage readings; and the usual gage may be altered for this purpose by setting the dial relatively back, or the index finger forward, so as to indicate substantially 14.7' under atmospheric pressure, as shown on Fig. 1.

' The combination is completed by the provision of an orifice 18, formed preferably in a removable orifice piece or nozzle 19 mounted at the outlet end of the pressure chamber, and a suitable coupling or union -20 connecting the chamber outlet to a passage or dis charge pipe 21' leading to any desired point or apparatus.

In this embodiment the orifice 18 has an effective discharge area or opening of .0195 square inch. It is preferably shaped with a tapered approach to the throat and a flared getaway, as indicated, the throat being scientifically bored or reamed to the exact size regulred. The orifice however may be formed 1n other ways. By the word orifice it is not intended to limit the element to a single ap erture, so long as there is the effect of a single aperture of the area stated, the purpose being to permit the outflow of the steam with a restrictive effect, giving progressive-escapement to a place of lower pressure.

With' the described embodiment the reading of the gage 14 gives directly the absolute pressure and at the same time gives directly theexisting rate of flow in pounds per hour.

Asan apparatus the disclosure combines the pressure chamberthrough which the steam flows, the pressure gage graduated to indifrom time to time, and thus give the means of determining the total weight of steam passing through the pressure chamber in any given period of time.

Fig. 2 shows an embodiment wherein a means is introduced ahead of the pressure chamber and gage by which the initial orboiler pressure can be reduced, and the rate of flow can be regulated. Thus the initial-or boiler pipe 23 is shown as leading to a suitable valve, such as a globe or throttle valve 24,

from which leads the pressure pipe 10 to the orifice unit or element 11 corresponding substantially with Fig. 1. By' reducing the steam pressure ahead of the gage a more advantageous workin pressure for the gage may be obtained an at the same. time the expansion operates to evaporate any contained moisture, so that only dry steam will pass from the pressure chamber to the orifice. Preliminary reduction of pressure may be effected by one or more successive orifices, or, I

if constant pressure and flow are desired, notwithstanding variability of initial pressure,

by an automatic reducing valve. By having a valve 24 adjustable manually, however, the total rate of steam flow may be regulated at will to any desired amount under guidance of the age acting as a flow indicator.

In this embodiment the orifice unit 11 is shown of generallypearshape with a threaded entrance 25 surrounded by a flange or hexagonal bead 26 facilitating the assembly'of the parts; while the lower end of the unit may be formed with an exit 27 having interior and exterior threads, the orifice piece 19 being screwed into the interior thereof while the exterior-is engaged by an outlet coupling 20 as in the case of Fig. 1. -The orifice nozzle can be placed at any point in the line of flow. A pi tail-tube 13 is shown connecting the cham er with the gage 14. v,

This embodiment is useful in oil refining, and for various other purposes, for example, in gas ovens or furnaces, where pressure or temperature is to be regulated, and properly proportioned quantities of gas and air or.

and illustrates the use of an orifice system 7 comprising several orifices in tandem, with the gage pressure taken off at a suitable point a in advance of the final orifice. The main orifice unit or pressure chamber 11 is connected by pigtail tube 13 with gage 14 as before. Preceding these elements is an orifice unit 29 containing an orifice 30 delivering into the pressure chamber 11; and preceding the unit 29 is an initial pressure pipe 23 lead ing from the boiler or source. Each of the several orifice'elements is shown as having two hexagonal flanges or beads, 26, one at each end, to facilitate assemblage. The

- orifice member 18 which cooperates with the pressure gage is mounted in the unit 11 and discharges into a succeeding unit 31, which may or may not contain an additional orifice member, and which is connected by a coupling 20 to an outlet pipe 21 as before. The controlling valve 32 is located at the far end of this pipe and delivers by the final outlet pipe 33 to the point of use of the delivered steam.

' This embodiment is useful in cases where any apparatus is to be supplied with low pressure steam from a high pressure source or boiler, the regulating valve being usually near the apparatus consuming the steam.

' When .no steam is being drawn the gage will indicate the full boiler pressure, but when the distant valve 32 is opened the gage will show,

not merely the reduced pressure in the chamber 11 but the rate of steam flow to the distant point, the orifice member 18 being pf the predetermined area stated. The preliminary orifice 30 is useful as without it the full boiler pressure will continue up to the second orifice. The first orifice acts as a variable pressure reducer, bringing the pressure to a moderate figure. When the initial pressure is Very high the number of orifices may be increased to three or four or more so as togive the desired pressure reduction. and the gaging of the rate of flow may be taken at any point in the system so long as the steam passing from that point next traverses an orifice of the proper area into a pressure not more than 58% of the gaged pressure. This ap plies in cases where the critical pressure ratio is 1.00 to 58, and the invention is operative where the absolute pressure ratio is substantially not higher than the critical ratio below which the rate of flow is proportional to the higher absolute pressure without respect to the lower pressure. 1

In a case, such as Fig. 3, where tandem orifices are employed, they may usefully be of progressively increasing areas; for example if each orifice is about 72% greater than the preceding, the percentage of pressure drop will be about the same at each point, and will be 42% in amount, or to a pressure 58% of the preceding, thus ensuring the operativeness of the flow measuring system wherever the gage be applied.

Fig. 4 is a further embodiment in which several additional features are disclosed, which may be employed jointly or separately. Thus where an orifice of size .0195 square inch is inadequate to carry the intended flow the invention may be employed as at the lower side of Fig. 4 with an orifice of a simple multiple of that size, for example .0972, enabling the absolute pressure gage to indicate the rate of flow by multiplying the readings by the simple factor 5; or in some cases by adding to the same pressure graduations on the dial the multiplied set of numbers indicating the flow. The arrangement would be the equivalent of five orifices of the base or key size .0195 delivering into the same outlet. Fig. 4 shows also the principle of supplying two or more different points of consumption with steam from the same pressure chamber, under observation or control of the same gage. In some cases it ma be desirable to supply unequal rates of ow to two different points, with correctly proportioned rates to each, and Fig. 4 illustrates this in employing the key size orifice .0195 at the nection 13 to a gage 14. At the upper side the pressure chamber discharges through an element or union 35 containing an orifice nozzle 36 which in turn discharges into passages 37 leading to one point of consumption. At the lower side of the chamber discharges to an element 35 containing an orifice nozzle 36 which discharges into passages 37 leading to another point of consumption. The upper orifice may be .0195 and the lower one .0972 square inches in effective area. arrangement the gage indicates the existing pressure in the chamber 11 and the several outlets will draw from the chamber of that pressure. The flow through the upper orifice 36 will be at a rate indicated directly by the pressure reading on the vgage whereas the ow through the lower orifice 36 will be at With this case the identical graduations of the dial serving for indication of both pressure and rate of floW.

The Fig. i embodiment is useful for many purposes, for example, introducing steam to a plurality of sprays in continuous oil stills; or the like, for which use the two orifices 36 and 36 will usually be equal, and the pipes 37 and 37 leadingto the sprays, under regulation of Valve 24, by which the rate of flow is adjusted to the desired figure. A former element of uncertainty in continuous still work is thus removed, and the positive control of the amount of steam delivered makes for indicated by an inscription such as steam' flow in 5 lbs. per hour. Or the same marks may have two sets of numbers, as shown in Fig. 5, one giving the pressure, the other the flow; and if only the flow readings are inscribed the pressure is readily known by dividing by the factor 5, since the identical graduations apply to both.

Fig. 6 shows a pressure gage of the record ing kind which may be used with any of the disclosed embodiments, for example in Fig. 4. The gage for example may be the well known Bristol recording gage 39 supporting a pen or stylus 40 which traces the record, while internal clockwork rotates the dial or chart 41, which is removable or interchangeable. As the pen swings outwardly across the successive circles 42 it indicates increase of pressure in the orifice chamber, and these circular graduations on the chart may be numbered to represent the absolute pressure,

or the rate of flow, or both. The successive curved radii 430i? course indicatethe'hours of the day and night, so that the rate of flow at any time as traced b the record line 44 can be ascertained by re erenee to the proper hour radius. When the multiple size orifice is used as at the lower side of Fig. 4 it is convenient to inscribe upon the recording chart the proper multiples of the pressure, so as directly to read the flow on the pressure graduation lines, the pressures in that case being immediately determinable by dividing by the given factor, such as 5.

The practical use of this invention is high- ]y convenient, as is also the supplying of apparatus for any given conditions, and the testing and. calibrating of apparatus; alLof which are separately performed. For example where in the same plant, department, or

system there is need for a wide range of flow indication and regulation, requiring several different orifice combinations, the gaging or recording instruments can all be identical and can be interchangeable, and can be calibrated and tested by the N o. l or unit ratio or direct reading chart or dial; whereas in the industrial use of the apparatus the operatives are not concerned with the calibration, and frequently not with the pressure indication but only with the reading of rate of flow, and the regulation and recording of flow rate. The department of adjustment or repair has merely to select the proper orifice or orifices for the total multiple appropriate for each use and supply the corresponding dial or chart. This need not concern those using the apparatus in the field, and the operations are thus kept distinct, while a great variety of uses is readily covered with a minimum change of apparatus, .an orifice piece and a chart. Y

The calibrated orifice pieces are preferably numbered according to their area No. I being the base or key area .0195, No. 2 twice that area, etc. WVhen a total flow of say 25 times the unit is desired it is not necessary to use a N o. 25 orifice, as the combination of a No. 10 and No. 15 in parallel will give the result. 1

The herein disclosed system of gaging an regulating flow is found in practise to be not merely simple, convenient, inexpensive and durable, but highly accurate, namely to a fraction of 1% of error; which is much closer than the ability of an operative to effect adj ustment by observation. The immediate response of the gage to the adjustment enhances accuracy. The ready and reliable capacity to secure at will a given rate of flow avoids waste and excess, and thereby brings about substantial economies in steam and fuel besides the other advantages enumerated.

There has thus been described particular methods and apparatuses for the measurement, and thereby for the regulation, of flow of steam or other fluid, embodying the principles of the invention; but since many matters of method, apparatus, operation, ar-

rangement, combination and detail may be variously modified without departing from such principles it is not intended to limit the invention to such matters except so far as specified in the appended claims. lVhat is claimed is: y 1. Apparatus for measuring the rate of flow of gas from a higher into a lower pres-' .sure, where the absolute pressure ratio is substantially not higher than that critical pressure ratio (aslOO to -58) below which rate of flow is proportional to thehigher absolute pressure irrespective of the lower pressure,,

said apparatus "comprising a pressure chamber through which the gas flows at-the higher pressure, and a pressure gage connected thereto having its graduations based upon the absolute pressure in the chamber and ex: pressed in force units per area unit, (as pounds persquare inch), the chamber having a restrictive outlet of such predetermined characterv or area that the-rate of gas through the chamber and outlet, in quantity units per time unit, (as pounds 'per.hour), is readable upon the pressure graduations of the gage.

2. Apparatus for measuring the rate of. flow of gas from a higher into a lower pressure, where the absolute pressure ratio is substantially not higher than the critical pressure ratio of about 100 to 58 below which the rate of flow is proportional to the higher absolute pressure irrespective of the lower pressure, said apparatus comprising a pressure chamber through which the gas flows at the higher pressure, and a pressure gage connected thereto having its graduations out to correspond to the absolute pressure in the chamber and expressed in force units per area unit, the chamber having an outlet orifice of eflective area such that the rate of gas flow through the chamber and outlet, in quantity units per time unit, is readable upon the pressure graduations of the gage.

3. Apparatus for measuring the rate of flow of dry steam from a higher into a lower pressure, where the absolute pressure ratio is substantially not higher than the critical pressure ratio of about 100 to 58, said apparatus comprising a pressure chamber through which the-gas flows at the higher pressure, and a pressure gage connected thereto having its graduations based upon the absolute pressure in the chamber and expressed in pounds per square inch, the chamber hav-' ing a restrictive outlet of such predetermined character that the rate of gas flow through the chamber and outlet, in pounds perhour, is readable upon the pressure graduations of the gage.

4. Apparatus as in claim 3 and wherein the outlet consists of an orifice of effective area of about .0195 square inch multiplied by an integer.

5.' Apparatus for measuring and regulating the rate of flow of gas from a higher into a lower'pressure, where the absolute pressure ratio is substantially not higher than laid.

that critical pressure ratio below which rate u of flow is proportional to the higher absolute pressure irrespective of the lower pressure, said apparatus comprising a pressure chamber through which the gas flows at the higher pressure, a pipe connecting the initial pressure source with the chamber, a valve interposed in the pipe for taking down and regulating the pressure in the chamber'and thereby the rate of flow, under. guidance of the gage next recited, and a pressure gage connected with the chamber having its, graduations based upon the absolute pressure .in the chamher; and expressed in pressure units per area unit, the chamber having a restrictive'outlet of such redetermined character that the rate of gas ow through the chamber and outlet, in quantity units per time unit, is readable upon the pressure graduations of the gage.

6. Apparatus as in claim 1 and wherein the pressure chamber is provided with a plurality of separate restrictive outlets bearing a simple relation to each other and delivering to separatepassages for measured distribution of gas to different points all under indication by the same pressure gage. 3

' .7. Apparatus as in claim 5 and wherein the pressure chamber is provided with separate restrictive orifice outlets of different effective areas bearing a predetermined simple ratio to each other, delivering the gas at proportioned rates to separate passages all under indication by the same gage and regulation by the same valve.

8.- Apparatus for measuring and regulating the flow of gas comprising a regulating valve delivering to a pressure chamber, such chamber, a pressure operated gage connected with such chamber and adapted to indicate the absolute pressure therein, said chamber'having a plurality of restrictive outlets ofdifi'erent efiective areas, which are such that the respective rates of flow through the outlets will each be expressible as an integral multiple of the gage indication, when the ratio of the absolute pressure in the chamber to that of the passage, into which the flow is directed, is' than the critical pressure ratlo,

not greater said outlets delivering to separate passages.

In testimony whereof, I have aifixed my signature hereto. Y

' GRANT CAMPBELL. 

